This was originally written a long time ago and I recently found
it in a file. So here it is for the world to have just in case someone actually
needs to mod a MASTR II. I take no responsibility for the following. This is
presented as a public service.

1. Remove C228, C230, C243, C244, C246, C263, R207 and L209, L210, L211,
L213 and K201. (Remove K201 for repeater service only)
2. Replace Q203 with a PT8874A.
3. Replace C212 and C213 with 70pF uncased mica.
4. Replace C218 with 10pF uncased mica.
5. Replace C220 and C221 with 150pF uncased mica.
6. Replace R208 with a 0.68uH inductor.
7. Install a 10 ohm, 1 watt resistor from the base of Q203 to ground.
8. Install a 47pF uncased mica from the intersection of R203, L201 and T201
to ground.
9. Install a 1K 1/4 watt resistor and an ARCO 404 from the intersection
of CR201 and T201 to ground.
10. Install two 50pF chip caps from the base of Q202 to ground. Caps should
be installed next to C212 and C213.
11. Install an ARCO 404 from the collector of Q203 to ground.
12. Install an ARCO 404 from the intersection of C231 and T204 to ground.
13. Install a 43pF chip cap from the collector of Q203 to ground.
14. Remove trace between L209 and L208.
15. Remove trace between L211 and L210.
16. Install jumper to bypass the T/R relay from the trace going from L213
and the "ANT" connector. (Repeater service only.)
17. Replace L209 with a #18 jumper.
18. Install a 7pF uncased mica from the L209 jumper to ground.
19. Replace L212 with a #18 jumper.
20. Install a 7pF uncased mica from the L212 jumper to ground.
21. Cut the trace between C245 and L211.
22. Install a coil, 4 turn #18, 1/4" diameter, between L211 and L212
and between both shields inside the low pass filter assembly.
23. Install a 15pF uncased mica from the center tap of the coil, described
in step 21, to ground.